Born in Siena around 1350, died in Venice in 1434. He entered the Dominican Order at a young age at S. Domenico in Camporegio. From as early as 1364, he was personally and epistolarily acquainted with St. Catherine. Lecturer in theology in Genoa in 1391, after a journey to the Holy Land he settled in Venice (November 1394), became provincial of the province of Greece (1397), prior of SS. Giovanni e Paolo in Venice (1409-11), and of S. Domenico di Castello (1414-22).
He played a quite special role in the history of the Dominican Third Order and the cult of St. Catherine. In 1396, the Blessed Raymond of Capua entrusted him with the direction of the Mantellate in Venice. In 1401, Fr. Tommaso da Fermo appointed him vicar general for all the Mantellate in Italy and charged him with the negotiations for the canonization of the Sienese saint and for the approval of the Rule of Muñoz da Zamora. He composed a Treatise on the Third Dominican Order, of which the first part was completed in 1402, the second in 1407, and the third, which is a collection of letters of indulgence, seems to have remained incomplete after 12 August 1407.
Following the example of their confrères in other cities, the sons and daughters of St. Dominic in Venice adopted the custom of commemorating with a certain solemnity the anniversary of the death of Catherine of Siena. In 1411, following a dispute about this custom between devotees and opponents of the Sienese saint, a delegation of Dominicans asked the bishop of Castello to open an inquiry which would aim to demonstrate the virtues attributed to Catherine of Siena. Caffarini initially managed the affair concerning the Catherinian virtues known as the *Processo Castellano*. It was presented to the episcopal curia of Castello and contains 23 depositions (Dominicans, other religious, laypeople), with 2 supplements and 1 letter from Cardinal Giovanni Dominici, collected between 1411 and 1416. The importance of the inquiry and the information it contains is great. Laurent has highlighted the history and the historical and juridical value of these Castellano depositions.
He worked extensively on two other manuscripts about Catherine, namely shortly before and until 1411 on the *Supplementum* to the Catherinian legends of Capuano (*Proc. Cast.*, LXI-LXVII), completing it between 1416-18 in the form in which it has come down to us (ibid., LXI), while in 1412-13 he delivered in writing the first version of the *Legenda minor*, which had a second redaction in 1413-14 (ibid., XIX-LXI). Caffarini also collected Catherinian letters.